Blue Hill Observatory
September 2014 Summary:
The month was notable for being generally warm, very dry and much sunnier than average. The 24-hour mean temperature for the month of 64.4F was 3.2 degrees warmer the 120-year average for September, and this was about two degrees warmer than the 1981-2010 30-year average. The maximum temperature for the month was 91F on the 2nd, and the coldest temperature was 43F on the 19th. Daily temperature records during the month included 84F on the 27th, which tied a record set in 1998, and 86F on the 28th, which surpassed the previous record of 82F in 1959. The month was the driest September on record with a precipitation total of only 0.41 inches, which was about three and a half inches drier than both the 120-year average and the 1981-2010 mean. There were only five days with measurable precipitation during September, though this was more than the fewest number on record of three in 1908 and 1941. Thunderstorms were observed on two days during the month, which is average, and the annual total of 19 thunderstorm days is two fewer than average through September. The mean wind speed for September was 10.5 mph, which was the lowest on record for the month, and the prevailing wind direction for the month was WNW. The peak wind gust was only 33 mph from the SSW on the 6th and from the W on the 22nd, which was the lowest peak gust in September since at least the middle 1960s. September was very sunny with bright sunshine totaling 240.0 hours or 67 percent of possible, which was 11 percent more than the 120-year average for the month.